The present invention relates to display technology. Advances in display technology have led to the display of higher resolution images on many different screen sizes and in many different formats. These advances are not limited to applications using traditional cathode-ray tube (CRT) technology but also include projection displays, small near-to-eye (NTE) viewers in cameras and head mounted displays, consumer projector devices and even large digitally-based theatre projectors.
Some display applications utilize liquid crystal display (LCD) technology to display images. Three LCDs in an LCD projector individually modulate red, green and blue light respectively to form images on a projector screen or surface. Typically, the individual chromatic signals from the respective LCDs are combined within the projector device before being projected out to the screen. While the LCD projector tends to work well, it can be bulky and less portable due to this complex light-modulation mechanism within the projector.
Another technology used with displays referred to as a digital light processor (DLP) projection display uses Digital Micromirror Device (DMD) technology. The DLP projection display is often implemented using rear-projection screens or also in projector devices. The DMD portion is a semiconductor-based array of reflective mirrors that move quickly to modulate light. Lower cost DLP systems have a single DMD and a rotating color filter system in front of a light source synchronized to time-share working with the single DMD. These single DMD systems rely on the human visual system to integrate the three chromatic signals generated over a short time period into a crisp color image. Higher end and more expensive DLP systems are generally equipped with three DMDs to accommodate each of red, green, and blue colors to produce higher quality images. Overall, the DLP and DMD projection technology improves portability as the resulting equipment is often lighter and more compact. The light mechanism used to modulate the colors in DLP or DMD is not as bulky or complex compared with similar equipment used on the LCD based projectors.
Costs for the DLP and DMD technologies are quite high to most manufacturers. For at least these reasons, it would be useful to have an alternate technology for producing low-cost and high quality display devices.
Like reference numbers and designations in the various drawings indicate like elements.